If you want the science rather than the rhetoric, click here:
http://jag.cami.jccbi.gov./cariprofile.asp
and calculate it for yourself. You can also download the more advanced version and make more accurate calculations using waypoint, altitude etc.
The exposure level accepted for 'radiation exposed workers' i.e. us, varies depending upon to whose rules you beholden. The Euratom directive recommends not more than 20 mSv, whilst the US Dept of Energy use 50mSv. You can find the recommend maximums online also although I don't have the URL's handy.
Happy frying!